Track link assemblies for track-type construction equipment generally include a number of track bushings and entrained track links, driven by a sprocket. One of the main causes of damage to the track bushings is wear, such as abrasive or sliding wear. Wear may result from the harsh, contaminated environments in which the track assembly operates. For example, during operation, the bushings may be exposed to debris, soil, rocks, sand and other abrasive materials. These materials may accumulate between the engaging surfaces of the track bushing and the drive sprocket teeth, directly grinding, wearing, pitting, scratching, and/or cracking the surface of the track bushing and sprocket. As the sprocket continues to drive the track, the wear may degrade the outer diameter of the bushings and sprocket profile, limiting the life of the track link system.
Typical track bushings may be formed from materials that are hardened to decrease wear and increase service life. For example, typical track bushings may be case hardened by carburizing the bushing material. However, these materials and methods may still result in a relatively short service life.
One method for extending the life of a track bushing includes bonding a coating to the exterior of the track bushing. One example of this method is disclosed in U.S. Patent Publication No. US 2003/0168912 to Wodrich et al. The '912 publication discloses a track pin bushing having a metallurgically bonded coating disposed about its circumference. The coating is formed of a fused alloy that contains little or no inclusions. The alloy is formed first by generating a slurry of polyvinyl alcohol and a finely divided powder. Then, the slurry is applied to a bushing, dried, and fused to form the coating. However, the coating described in the '912 publication may not provide a level of wear resistance to a bushing that may be obtained using alternate methods. Accordingly, wear surfaces on components of endless tracks, such as track bushings, that provide acceptable wear resistance are desired to reduce the long-term maintenance cost associated with endless tracks.
The material and processes disclosed herein are configured to overcome one or more of the deficiencies in the prior art.